1. Install Linux (must be at least the 2.2 kernel)
1a. Login as "root"
1b. Install latest JDK from IBM AlphaWorks
2. Create a user called "notes" in the group "notes"
3. Download the R5 TAR file from Lotus
3a. If you have downloaded the multiple TAR files: cat *.tar > 5011lis.tar
4. Un-archive the TAR file: tar xvf 5011lis.tar
5. Do a cd to the directory where "install" exists (where license.txt also is)
5a. Run "./install"
6. Answer the questions, "notes" is the user, "notes" is the group
7. Change directories and start the setup program
7a. "cd /local/notesdata"
7b. Run "/opt/lotus/bin/http httpsetup"
8. You should see "the HTTP Setup is running"
9. From Netscape open "http://your.server:8081/"
10. Configure the Notes server as you would on any other Unix system
11. The server will stop
12. Change directories and start the server
12a Login as notes
12a. "cd /local/notesdata"
12b. Run "/opt/lotus/bin/server"
Another good article is available at LinuxWorld.